To provide a device detecting an accident in a power system exactly and a device detecting an accident in the power system and determining whether or not the accident exists on commercial system side.
This accident detection device for power system detects accident in a power system subjected to linkage operation through a separated breaker 4, in which a commercial system 1 and a distributed power source 3 for private use are inserted in a linkage bus 7, whereas it is determined as being an accident in the power system for annunciation if both of a voltage change component obtained by subtracting phase-to-phase voltage at that time from phase-to- phase voltage in the normal case and current running through the breaker 4 are above a prescribed level.
TAKASAKI YASUO
SHIBATA KAZUO
